Continuous furnaces



Nov. 4, 1958` R. Bucci 2,859,023

J CONTINUOUS FuRNACEs f Filed March 15, 1957 v 4vsheets-s11eet 1 m NINVENToR.

BY 7%@ W R. Bucci CONTINUOUS FURNACES 4 Sheets-Sheet 2 Filed March 15,1957 Nov. 4, 1 958 R'. uccl CONTINUOUS FURNACES 4 Sheets-Sheet 5 FiledMarch 1:5,l 195'! IN VEN TOR. @Yau/f am' m NQV. 4, 1958 R, Buccl2,859,023

- CONTINUOUS FURNAcEs l V Filed March 1:5. 1957 4 sheets-sheet 4 INVENTOR.

fwd@ BY m7,

States APatent O ,CONTINUOUS FURNACES Robert Bucci, Amhridge,Pa. iApplication March 13, 1957, Serial No. 645,799

6 claims. (C1. 263-6) This invention relates to new and usefulimprovements in continuous furnaces for reheating wrought iron or steeland it is among the objects thereof to provide a reheating furnace inwhich the furnace hearth for supporting the metal is especially designedfor reheating 4wrought iron.

It is a further object of the invention to provide a continuous heatingfurnace with conveying means normally disposed below the surface of thefurnace hearth away from the high temperature prevailing within thefurnace chamber, the conveyor being operative for raising the metalbeing heated above the hearth and advance the same in the direction ofthe discharge end of the furnace.

It is a further object of the invention to provide such conveying meansmounted on a vertically movable support or elevator whereby the entireconveyor may be simultaneously raised or lowered in relation to thefurnace hearth.

It is a further object of the invention to provide conveying means forcontinuous heating furnaces in which the carriers that engage andsupport the billets or slabs while being conveyed above the furnacehearth are water cooled. i

It is a further object of the invention to provide a continuous furnacefor reheating wrought iron billets or slabs in which the furnace hearthor bottom is provided with slag drains for sloping areas, the slag beingreceived in water troughs below the hearth drains by means of which theslag is washed away.

It is still another object of the invention to provide a singlecontinuous heating furnace for wrought iron billets or slabs which shalleliminate the need of a series of individual heating furnaces with theirattendant high labor cost.

The invention will become more apparent from a consideration of theaccompanying drawing constituting a part hereof in which like referencecharacters designate like parts and in which:

- Figure 1 is a side elevational view, partially broken away, of acontinuous heating furnace and conveying means embodying the principlesof this invention;

Figure 2 is a vertical section taken transversely of the view shown inFigure 1 Figure 3 is a side elevational view of a conveyor and support;

-Figure 4, an isometric view of a carrier used on the conveyor;

Figure 5, an end elevational view of a portion of the water coolingsystem for the carriers;

Figure 6, a side elevational view of the furnace hearth and conveyorsupport; and,

Figure 7, atop plan view thereof.

With reference to Figure 1 of the drawing, the furnace proper consistsof buckstays 1 supporting a lire brick wall 2 and roof structure 3, thebuckstays being mounted on a superstructure of structural steelgenerally designated by the numeral 4 and `reinforced concreteV ICCwalls 5. The furnace hearth designated by the numeral 6 is made of rebrick 7, as shown in Figure 2 of the drawings, there being slag drains 8spaced at intervals throughout the furnace hearth, the slag drainsdraining sloping areas as indicated by arrows in Figure 2 of thedrawing.

The numeral 9 designates the charging end of the furnace and the numeral10 the skid by which the billets or slabs are discharged from thefurnace to a receiving table 11, as shown by arrows.

The numeral 12 designates an inspection door of which there may beseveral on both sides of the furnace through which the billets or slabscould be manipulated or turned, if so desired.

With reference to Figure 2 of the drawing, the hearth is provided with apair of slots 13 and 14 extending the length of the furnace throughwhich carriers 15 of a conveyor can be raised above the furnace hearthfor lifting the slabs or billets from the hearth and advancing them inthe direction of the discharge end of the furnace. The carriers 15 aremounted on an endless `chain 16, Figure 3, that passes over a drivewheel 17 `nels and I-beams generally designated by the numeral 27 thatconstitute an elevator that extends the full length of the conveyor.

`As shown in the several ligures of the drawing, particularly Figure 2,the elevator 27 is provided with jack screws 28 and 29 having worm gearwheels 30 and 31, respectively, that are engaged by the Worm 32 of adrive shaft 33 that is driven by gear wheels 34, 35 and 36, the latterbeing the pinion gear of a drive motor, not shown. Thejacks and wormwheels and worm drives are suitably journaled in pillow block bearings37. There may be three or more sets of jack screws spaced longitudinallyof the furnace beneath the elevator 27 driven by a common shaft 33 andwhen the drive motor is energized, the jack screws will functionsimultaneously to raise or lower the elevator 27 that supports theentire conveyor mechanism. In this manner the carriers 15 will be raisedor lowered with reference to the furnace hearth, line 6, Figure l.

Y With reference to Figure 2 of the drawing, gutters 38, 39 and 40 aredisposed below the slag drains 8. Burners 41 are provided beneath theslag drains 8 to keep them hot and water sprays 42 are provided in theslag troughs to sinter the hot slag as it falls into the trough orgutters which are inclined to wash the sintered slag away from beneaththe slag drains.

With reference to Figure 4, it is to be noted that the carriers 15 arehollow and are provided with ilanges 43 with holes 44 for attachment tothe chain links 16. Each carrier is provided with threaded openings 45and 46 for connection with fluid conduits to deliver a coolant such aswater to the interior of the carrier wherein it is circulated to coolthe same and drained through the other opening. These individual inletsand outlets are connected by ileXible, preferably helically shapedconduits 47 or flexible hose connected to a common reservoir 48 that ismounted on the ends of the shaft 25, as shown in Figure 2. As shown inFigure 5, conduits 47 will stretch from the reservoirs 48 which are onthe shaft 25 at the center of the conveying mechanism and follow thecarriers 15 on around the endless conveyor without crossing or becomingtangled.

4skid 10 onto the receiving platform or table 11.

In the operation of the above-described continuous heating furnace, asuitable combustion system, not shown, is utilized. Such a system isusually operated with a recuperator to obtain economic operation by heatexchange to absorb the heat from the waste products of combustion andthrough the heat exchanger to preheat the air delivered to the fuelburners. Since the combustion system is no part of the presentinvention, it is not shown.

The products of combustion are drawn from the rear or center of thefurnace chamber to the front end and exhausted through the passages 50and 51 leading to a stack or the inlet side of a recuperator structure(not shown). The connecting passages may be formed by metal orrefractory construction.

Also, if during the operation of the furnace the pressure within thefurnace chamber is lowered due to opening of the side doors or for anyother reason and air passes up through the conveyor slots 13 and 14, thelatter may be sealed in any suitable manner or the space below thefurnace may be closed in with appropriate doors for access to theoperating equipment.

The operation of the above-described furnace and conveying system isbriefly as follows:

With reference to Figure l, the billets or slabs are placed on thecharging end of the furnace designated by the numeral 9 in the drawing.The conveying system is then brought into action by raising the elevator27 through operation of the shaft 33 that raises the jack screws 28. Asthe conveyor is raised, the carriers will extend through the slots 13and 14, Figure 2, and engage the billets or slabs resting on thecharging end 9, Figure 1, and convey it forward towards the dischargeend. Each time the billet or slab has been advanced a desired distance,as for example the width of the slab, the elevators are lowered untilanother slab has been placed on the charging end 9 of the furnacehearth. When the elevator 27 is again raised, it will engage all of theslabs previously charged from the furnace hearth and advance themforward to the discharge end where the end slab will slide down the Eachtime the charge in the furnace has been advanced a desired amount, theelevator 27 is lowered to move the carriers below the hearth surface tothe position shown in Figure 2 of the drawing.

Wrought iron, when heated to the rolling point, gives olf slag whichmust be removed from the furnace bottom. As shown in Figure 2, slagdrains 8 are provided in sloping areas as indicated by the arrows, sothat the slag will drain off through the furnace bottom. The top portionof the slag drains 8 are kept hot by the heat of the furnace and thebottom portion will be kept hot by the burner jets 41, Figure 2, and theslag will not harden or freeze in the drain holes.

The arched openings 12 serve for inspection of the billets or slabs andfor refinishing the furnace bearth surface as by the application ofsand. The furnace walls and roof structures are preferably lined withhighly refractory fire brick such as silica brick, the brick beingsuspended from channel shaped steel structures in the usual manner. Theslag drains may be lined with high temperature tire clay and packed toform a hard surface, or special preformed lining sleeves of suitableclays may be inserted in the drain openings. Because of the hightemperature conditions prevailing in the furnace for reheating wroughtiron for rolling, provisions must be made to cool the doors and otherportions of the furnace, which is no part of the present invention.Suitable control levers for operating the elevator jacks and the endlessconveyor to move the carriers in the openings 13 and 14 of the hearthand indicating means for temperature and other operating characteristicsmay be provided in the usual manner so that substantially the entirefurnace operation may be controlled by a single operator.

Although one embodiment of the invention has been herein illustrated anddescribed, it will be evident vto those skilled in the art that variousmodifications may be made in the details of construction withoutdeparting from the principles herein set forth.

I claim:

1. In a continuous heating furnace for reheating wrought iron a hearthstructure having a plurality of slag drains extending vertically throughthe hearth spaced longitudinally and transversely of the furnace, thefurnace hearth having sloping areas converging in said slag drains andmeans for heating said drains throughout to prevent freezing of the slagtherein, said slag drains being disposed in rows and outside guttersdisposed beneath said rows of slag drains having water sprays forcooling and'sintering the slag and for washing the same down saidgutters.

2. In a continuous heating furnace a hearth having parallel slotsextending longitudinally thereof, conveying means the load supportingsurface of which is disposed below said hearth and being adapted to beraised through said slots to extend above the hearth surface, means forraising and lowering said conveying means operative to raise the billetsor slabs from the furnace lhearth for advancing the same towards thedischarge end of the furnace, and means for lowering said conveyingmeans to deposit the billets or slabs on the furnace hearth, saidconveying means being in the form of an endless conveyor having watercooled carriers for engaging and supporting the billets and slabs beingheated, said carriers being disposed below the hearth surface when nottransportingbillets or slabs through the furnace chamber.

3. In a continuous heating furnace for reheating wrought iron, parallelslots extending through the vertical dimension of the furnace hearth,endless conveyors beneath said slots having carriers mounted on anendless chain disposed in said slots, said conveyors being mounted on anelevator having means for raising and lowering the same to project thecarriers through the slots into the furnace chamber for advancingbillets or slabs through said chamber, the said slots in said hearthbeing of inverted V-shape and the carriers being of complementary shapebut of lesser dimension to be adapted to extend at least in part throughthe slots into the furnace chamber.

4. In a continuous heating furnace for reheating wrought iron, parallelslots extending through the vertical dimension of the furnace hearth,endless conveyors beneath said slots having carriers mounted on anendless chain disposed in said slots, said conveyorsibeing mounted on anelevator having means for raising and lowering the same to project thecarriers through the slots into the furnace chamber for advancingbillets or slabs through said chamber, the said slots in said hearthbeing of inverted V-shape and the carriers being of complementary shapebut of lesser dimension to be adapted to extend through the slots intothe furnace chamber, the endless conveying chain being disposed overgear wheels having sprocket teeth for engaging the `links of the chainand said conveyor having rests for supporting said carriers on thereturn strand of the conveying means, said rests having rollers at thesides and bottom to provide anti-friction contact with the carrier endsand walls.

5. In a continuous heating furnace for reheating wrought iron, parallelslots extending through the vertical dimension of the furnace hearth,endless conveyors beneath said slots having carriers mounted on anendless chain disposed in said slots, said conveyors being mounted on anelevator having means for raising and lowering the same to project thecarriers through the slots into the furnace chamber for advancingbillets or slabs through said chamber, the said slots in said hearthbeing of inverted V-shape and the carriers being of complementary shapebut of lesser dimension tobe adapted to extend in part through the slotsinto the furnace chamber and cooling means for circulating water throughsaid carriers.

6. In a continuous'heating vfurnace a hearth structure.

a furnace chamber constituted by the hearth structure, side walls and arough structure, the side walls having arched openings therein With doorclosures therefor, the furnace hearth having parallel slots extendingfrom the charge to the discharge end of said furnace, the latter beingprovided with skids for directing the materials from the furnace hearthto a receiving table, an endless conveyor beneath the furnace hearthhaving carriers mounted on4 endless chains, said carriers being disposedin the hearth slots, sprocket Wheels for said conveyor chains mounted onan elevator and carrier rests mounted on said elevator having rollersfor making anti-friction contact with the conveyor carriers, saidelevator constituting structural steel members supported on a pluralityof screw jacks, worm wheels for rotating said screw jacks and a wormshaft engaging said worm wheels, said worm shaft being connected to allof the Worm Wheels to actuate the jack simultaneously to raise or lowerthe elevator, water reservoirs mounted for rotation on a centralconveyor sprocket Wheel shaft to be rotatable therewith having flowconduits connecting said reservoir to said carriers to circulate watertherein, said furnace hearth being sloped and being provided with slagdrains, the high points of the sloping hearth being at the slots for theconveyor carriers.

References Cited in the file of this patent UNITED STATES PATENTS671,893 Laughlin Apr. 9, 1901 694,569 Nau Mar. 4, 1902 1,209,021Phillips Dec. 19, 1916 1,452,045 Hawley Apr. 17, 1923 1,878,896 SessionsSept. 20, 1932 2,028,941 McIntyre Ian. 28, 1936

